There's also an illogic to the appeasement charge: because Russia opposed the missile sites, it does not follow that the U.S. decided to remove them to "appease" Russia's concern. Obama's premise is that the missiles -- leaving aside the open question about whether the technology works and whether it's cost effective -- were an irritant and a way for Russia to gum up negotiations on more important, more consequential decisions, like the stringency of economic sanctions against Iran, missile sales to Iran, and treaty negotiations.

The gamble here is that enough of the missile defense shield will be in place before Iran gets its act together. From a geopolitical perspective, poking Russia and Iran in the eye isn't worth the hassle.